Green synthesis of gold nanoparticles by phycoerythrin extracted from Solieria tenuis as an efficient catalyst for 4-nitrophenol reduction and degradation of dyes in wastewater

Algal blooms and untreated wastewater will destroy the environment and ecosystem on which human beings depend. In this study, Solieria tenuis, a potential bloom in some regions of the sea in China, was used to mediate the composite of phycoerythrin (PE) and gold nanoparticles namely Au@PE NPs via a quick, easy, and effective manner. The physicochemical properties of Au@PE NPs were determined through UV-vis spectroscopy (UV-Vis), fluorescence spectroscopy (FP), fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The composite materials with a fine morphology and size (average size of 16 nm) exhibited superior catalytic abilities for the conversion of 4-nitrophenol(4-NP) to 4-aminophenol (4-AP, k298K 1/4 0.36 x 10-2 s) and the degradation of cationic dyes methylene blue (MB) and safranine O (SO) in wastewater. Additionally, the mechanisms of 4-NP's catalytic reduction and decolorization of dyes by Au@PE NPs were proposed. The results indicated that PE could not only act as capping and reducing agents but also enhance solubility and photocatalytic activity of the synthesized gold nanoparticles. The current study provides clear evidence of a potential economic solution for utilizing organisms that are harmful to the environment to develop novel bioconjugated composites with multiple functions for efficient pollutant removal and environmental remediation.& COPY; 2023 Published by Elsevier Ltd.